Fire box



A. BURKART.

FIRE BOX.

APPLICATION FILED FEB. I3, 1920.

Patonted Oct um 0N am ww. I.. L1]

Patemea oct. 24, 1922.

.nur

AUGUSTIN nunnnn'nor BERN, SWITZERLAND.

f FIRE Box.

Application led February 13,` 1920. Serial No. 358,511.

To all' 'whom t may/concern:

Be it known that I, AUGUSTIN BURKART,

'a' citizen ofthe Republicl of Switzerland,

` My invention relates to iirebox construc-y tion Vand has for its primary object the pro- `vision of an improved construction for ire boxes whereby the air supply `to `the lire may be pre-heated at will, to the end that coal'may be saved, the production of smoke retarded, and a very complete combustion of coal attained.

Other objects andadvantages of my in- Vention will appear from the following description, taken in conjunction with the accompanying drawings which form a part of thisspecification andl illustrate the preferred embodiment of the invention.

In the drawings:

Fig. l is a front elevation of a lire box constructed in accordance with the princi` ples of this invention;

Fig. 2 is a section on line 2 2 of Fig. 1;

Fig. 3 isa Section on line 3-3 of Fig. `1.

Reference numeral 10 indicates a preferably rectangular frame of iron forming a part of the front wall of a fire box and which, by means of a rib 11, cast on its inner side, supports the forward end of the re grate generally indicated at 12; this re grate being in the ordinary manner supported above the bottom of the fire box to divide the same into an ash pit and a superposed fire chamber. frame 10 is formed with a box-like air chamber 13 the greater' portion of which is disposed below the level of the grate 12. The forward wall of chamber 13 is provided with a plurality of draft apertures 14: which may be opened or closed in the ordinary manner by meansof a similarly apertured slide damper 15 mounted to slide from right to left against the rearface ofthe front wall 16 of chamber 13. Normally the damper 15 is closed as seen in Figs. 1 and 2, but, by means of the usual handle 17 sliding in a horizontal slot 18 it may be opened wholly or partly at will. Above chamber 13 the frame 10 receives a box-like door generally indicated at 19, this door being provided with hnge lugs 21 to swing on a hinge pintle 22, the latter being carried in The lower portion of frame 10. In order to facilitate the closing and opening of thedoor 19, itsfree vertical edge, along the inner side, is curved away from frame 10 as indicated at 23 in Fig. 3. The door 19 has itsI forward wall 24 provided with a series of spaced vertical apertures 25 which are controlled by means of adraft gate 26 horizontally slidable against' the rearface-of wall 2st in theusual manner,` being movable to one side as indicated in dotted lines in Fig. 1 to partially or wholly open the apertures 25. The top horizontalwall 2710i: chamber 13 and the bottom horizontal wall 23 of the hollow door 19 are provided with registering apertures 29, while the rear vertical wall 31 of vdoor 19 is imperforate. A small. portion 32 lof the vertical inner wall of chamber 13 and the'entire inner wall 31 of door 19 stand above the top of'grate 12 and are' thus exf posed to the heat of the-fireon the grate.

In the operationof my invention, the gate 26 is irst closed, damper 15 opened, and a re started in the usual way, the fire receiving draft from apertures 14 of the draft chamber and oppositely positioned air apertures 33 provided in the inner vertical wall of the air chamber 13. As soon as the re is started the draft door 15 is closed and the draft gate 26 opened so that the air for the re is admitted through apertures 25 of door 19, impinges against the hot inner wall 31 of that door, passes downwardly through the apertures 29 into chamber 13, thence through the air apertures 33 to the lower side of grate 12. By the time the draft has 'reached the bottom of grate 12,A it is pre heated because of its contact with the heated inner wall 31 of door 19 and the heated portion 32 of chamber 13. the result being that the fire burns with a minimum production of smoke and an almost complete combustion of the coalfed to it. A further result of the maximum combustion of coal is a saving of fuel, inasmuch as less coal is needed to develop a given amount of heat than in cases where cold air is fed to the grate. Coal is fed to the grate in the usual way by opening door 19 and charging the fire by shovel or otherwise, following which door 19 is closed by the usual hand latch 34; and the draft gate 26 opened as shown in dotted lines in F ig. 1-or further if desired-to impinge the cold air against wall 31 before" it passes beneath the grate.

While I have illustrated and described the preferred embodiment of my invention, it is obvious that one Skilled in the art may make modifications thereof without departing,` from the spirit of the invention. l wish, therefore, not to be restricted to the precise embodiment shown except in so far as the same is limited in the appended claims.

I claim:

l. In ar lire boX,-the` combination `with meansdelining an air chamber located in front of and mainly below the grate level, said chamber being` apertured in its outer, inner and upper walls, of adamper controlling passage of air throughthe outer wall oftheair chamber, a hollow fire door positioned above said air chamber and having apertures which in the Vclosed position of the fire door register with the apertures in the top `wall of the air chamber, and the in'iperforate linner wall of the said lire door exposed to the heat of afireon the lire boX grate, a perforate outer wall for the lire door, and a draft gate controlling passage of airthrough the fire door.`

V 2. The combination with ,the grates of a fire box, of an air chamber extending below said grates, Said air chamber hming,` pei'- forated inner and upper walls7 a draft damper for controlling the admissionof air lire box, of a hollow box-like door pivotallv mounted above thelevel of said grate's, -saicl door having a perforated lower wall land being provided lupon its outer front/,wall with a draft gatefanair chamber rdisposed beneath `said doorand extending below said grates, said chamber having a perforatedl upper wall l communicating through the aforesaid .perforations with the interior of said door, and having'aperforated inner wall through which air is delivered beneath Said grates, and a draft chamber mounted on the outer wall of said fire fbox through which air may be admitted directly to the,

box when said chamber is open.l

jWitnesses J. AnLnNsoN, EZR REEDER.

' AUGUSTIN BUR-KARLT. 

